I will second this so hard, as it is my experience as well. Just staring slackjawed, mindlessly scrolling for hours on end, is a noticeable difference from writing code. I wish there were studies on these differences.
"Sedentary screen time Sedentary screen time is calculated in hours per week, adding together the participants’ answers to the questions ‘In a typical DAY, how many hours do you spend watching TV?’ (FC: 1070) and ‘In a typical DAY, how many hours do you spend using a computer? (not including time using a computer at work)’ (FC: 1080)."
https://bmcmedicine.biomedcentral.com/articles/10.1186/s1291...
Sure, that's at least an attempt. However would you characterize spending time on a personal project work? That's why I called out my specific examples of side jobs and hobby projects.
I'm not rejecting the findings In particular, maintaining optimal sleep and lessening screen time (which is often an issue in youth), while having adequate physical activity and good dietary quality, may reduce the symptoms of depression,” of lessening screen time in favor of more constructive activity like exercise. I'm suggesting there's probably room here for a deeper dive into the kind and quality of screen time, because even bucketing it into just work vs everything else is arguably too broad. I believe some kinds of screen time are constructive.